I wish I could program so I could add something to this project.
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
Thanks for the update Doug and once again, thank you for all the hard work you are putting in to this - it's really appreciated.
Cheers, Mark
Being in the software / hardware business for over 25 years and doing my share of startups I've learned a rule of thumb: is it is generally necessary to hire 6 software engineers for every hardware engineer. Software can be an order of magnitude more complex and take considerably more time to develop and test than the hardware. Software development is the most labor-intensive process of building any technological product and this is particularly true for embedded systems work like the OBC.
Toward that end I certainly hope more people come out of the woodwork to help develop the software. I'll do my part, especially initially, to validate the hardware, but I'd be lying if I suggested I have even a fraction of the time required to build and maintain all the software needed for this unit. I would be able to justify the time if I charged for it in the case of the turn-key variant, but I'm not looking that far ahead right now aside from making engineering decisions that will facilitate the eventual production of that variant.
Latest update on my project is available on the project page:
https://www.dvatp.com/tech/dvobc_project
Two of the planned expansion module boards have been designed and preliminary placement is complete. One of the boards is host to an automotive-grade GPS module and Bluetooth/WiFi module. The other is host to the K-bus transceivers, which have returned from the baseboard to ensure they are easily replaceable in the event they go boom and a single CAN bus interface with full interface protection worthy of an automotive environment. The CAN bus will allow communications with the DME on S54 conversions as well as dozens of other sensors, switches, etc, available from both BMW (from the E46) and the aftermarket.
dvobc_gwab_board_top_after_tented_guard_vias_small.png
dvobc_da_board_top_after_tented_guard_vias_large.png
Next up is the touchscreen LCD board.
I had a look through your project. I like seeing this project reborn. And this time I would be interested in contributing to it myself by becoming a registered developer.
As some of the members mentioned, I don't really see a need for BT interface. What for? OBC on E36 is fairly basic, because OBD is very basic as well, with only few interesting sensors available.
Of course, there is way more potential on newer cars. But I think you should concentrate on reliable and easily accessible board with a little bit of updated look.
I like your idea of LCD screen. But again... don't feel a need for a touchscreen as most of them just annoy me. Touching buttons is way more satisfying.
Our cars are old, we know it and we love it. So if we can do some new stuff with our old looking equipment - that keeps me happy.
The BT/GPS and Touchscreen capabilities will be OPTIONAL, so if you don't want those features you won't have to buy them. However, I need to develop them now to ensure they will work in the overall design. The same can be said for the touchscreen / turn-key variant.
As I indicated above the main reason I'm implementing BT is for over-the-air updates to make it easy to connect to the device via a computer / tablet / phone and update the firmware. Without this interface that process will be far more difficult. BT will also be quite handy for real-time and archived data retrieval -- think live data streaming from it around the track or collecting the data after a track session.
The touchscreen is being designed because it is the most cost effective way to completely replace the factory OBC case, keypad and display. The reason why most interfaces in vehicles today have moved to a touchscreen is that the software-based interfaces they enable make it far easier to access all of the information provided by the system. A software interface can also be changed far more easily than a hardware interface (i.e. a fixed function keypad). I have considered lining the left and right edges of the touchscreen with soft-keys for those that prefer tactile switch operations, but I haven't got that far in the design yet.
About a month ago, after evaluating several shortcomings of the existing design, I decided to further modularize the design. The result is in the form of a MCU daughtercard that mates with the baseboard. See the picture below.
The MCU daughtercard is host to all of the supporting MCU circuitry, JTAG chain, USB debug interfaces and expansion slots. The baseboard remains host to the IO protection circuitry, power supplies, high resolution ADC, and factory OBC keypad and LCD display interfaces.
This change has produced several positive impacts:
- The baseboard layer count has been reduced, which will reduce its manufacturing cost
- Fewer components on each board will make them easier to assemble manually on the bench during prototyping and cheaper to assemble on automated systems in production due to fewer reels on the PNP machine and faster setup.
- The additional space between the boards permits the placement of some larger (but less costly) components and provides additional headroom for EMC covers / screens for the switchmode supplies.
- The design is inherently easier to test. I can replace the MCU daughtercard with a "dumb" debug board that provides test points for the conditioned (i.e. ESD / surge protected) signals during the early design validation stage or attach "in circuit" debug boards to connectors on the bottom of the baseboard as required to connect a scope or logic analyzer.
This work set me back about a month but I think the end result will be worth it.
baseboard_v3_with_mcu_daughtercard_standoffs_2020_06_03.png
Last edited by dwvcfii; 06-03-2020 at 10:43 PM.
I think I understood half of that, but it sounds awesome.
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
So how many layers is the PCB board now?
Another update on my project, mostly to show the many boards assembled:
dvobc_2020_06_11.png
I've added an IO Debug board which attaches to the bottom of the baseboard to provide access to the signals going between the microcontroller and the baseboard. These are conditioned (level shifted / surge protected) signals safe for connection to a variety of test equipment including logic analyzers and scopes, as required to perform protocol capture and decoding for software development purposes. If it's not obvious, these boards are intended for development only and cannot be installed in the factory enclosure.
The next step in the development is the design of a third and final expansion module to provide access to the MCU's USB OTG peripheral along with limited 5V power so a variety of external devices like common flash drives can be powered by the OBC, followed by the design of the touchscreen LCD module. Then I have to do a bunch of design validation -- a tedious but necessary process before I can send the first boards out for manufacturing.
Sweet. Any indication, just a global idea when first production run? Q3/Q4 2020, 20201...
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
The last few weeks have not allowed me to work on the project very much but there is progress. I can finally see the light at the end of the tunnel of the design phase. Most of the changes are in the form of design validation and are thus not visible, but the one obvious change is the inclusion of the expansion module debug board (EMDebug) designed to allow the interception of signals on the expansion module interfaces. This board became necessary when I realized I simply would not be able to include any debug headers in the limited space available on the expansion module boards. Like the IODebug board, the EMDebug board is designed to mate securely with the MCU board so that the entire assembly can be brought into the vehicle without risk of the boards just snapping off. So the good news is that the design is now testable, which should make the initial bare-metal turnup a lot easier.
dvobc_2020_07_19.png
The bad news is the 'rona has turned out to be more of a curse than I thought it would be. I thought rational minds would prevail after a few months of shutdown and we'd have a v-shaped recovery since the shutdown was largely a policy decision. The reality, however, is that this promises to devastate one of the industries I depend on for money that pays for all of these "fun" (read: low margin, low volume) projects and the end result is I will have to dedicate more time to other products that will be produced in far greater volume to make up for the losses. That will naturally slow the pace of work on this project. I still intend to finish the prototype, but it will take longer than I expected.
As always, the most detailed and up-to-date information will always be found on the project page located here:
https://www.dvatp.com/tech/dvobc_project
If anyone has one of the original boards that they are not using, I would be interested in buying it. Any condition, with or without an OBC connected. Please email me through the forum if so.
No PMs. Email through forum please.
Id like to know how many were sold. I have one but Im keeping it.
2003 540i M Sport 6 spd, 97 328iC 5 spd w/M Lux Package, 95 525iT w/M52 5 spd swap, 2008 R1200GS Adventure, 92 Celica All Trac Turbo
Sure, just let me know what you want for it. Does it have the components or just the board?
No PMs. Email through forum please.
I have all kinds of info and files at home. PM me your email and Ill give you what I have once Im home again.
A years without an update. Hope it's still alive.
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
Updates?
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
My project is still dormant as I have been focusing on other higher-volume projects. Problem now is I can't get any parts for those either. It's utterly ridiculous that this country has outsourced virtually all semiconductor manufacturing.
Wish I could revisit this project sooner but with lead times for countless parts in excess of a year, it won't be anytime soon.
That too bad to hear, but good to know it's not a dead project.
1998 BMW M3 3.2 Cabrio Alpinweiί III on Schwarz German spec 1 of 12
SMG SRA PDC AUC OBC GSM HK UURS IHKA FGR MFL
IG: https://www.instagram.com/iflok/
Bookmarks